System and method for laser based treatment of soft tissue

ABSTRACT

The disclosed invention relates to an improved system and method for treatment of soft tissue, e.g., for treatment of a snoring condition. The system can include a laser source; a hand piece; and a device for directing radiation emitted by the laser source to a treatment area (e.g., an oral treatment area). In some cases, the handpiece can include an optical element (e.g., a lens) mounted within a replaceable cartridge and adapted to modulate a laser beam such that it is non-ablative, prior to its delivery to a treatment region. In various embodiments, the system includes a CO2 laser capable of performing treatment in a more efficient manner than conventional techniques.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/173,792, filed on Feb. 11, 2021, which is a continuation of U.S.patent application Ser. No. 16/993,991, filed on Aug. 14, 2020, now U.S.Pat. No. 10,945,790, and claims the benefit of priority to U.S.Provisional Patent Application No. 62/887,949 entitled “System andMethod for Laser Based Treatment of Soft Tissue,” filed on Aug. 16,2019, the contents of which are incorporated herein by reference intheir entireties.

FIELD OF THE INVENTION

The present invention generally relates to the treatment of soft tissueusing a light-emitting device (e.g., a laser source) and, moreparticularly, to contracting and stiffening of soft tissue by directingradiation emitted by a laser source to a treatment area, e.g., to treata snoring condition.

BACKGROUND OF THE INVENTION

Snoring is a very common and generally undesirable form ofSleep-Disordered Breathing (SDB) which affects more than 30% of theadult population and a comparable percentage of children andadolescents. The sound of snoring is usually a consequence of thevibration of pharyngeal soft tissue caused by a partial upper airwaycollapse during sleep. Snoring can cause sleep deprivation for bothsnorers and those around them and patients can suffer from severe issuesthat can lead to heart attack and stroke. [Ref: A clinical approach toobstructive sleep apnea as a risk factor for cardiovascular disease,Vasc Health Risk Manage 2016; 12:85-103].

Various treatment modalities for SDB have been recommended to reducethese vibrations. These techniques include preventive management, use oforal appliances, conservative treatment (continuous positive airwaypressure (CPAP) devices), and surgery/laser assisted therapies [Ref sFiz J A, Morera Prat J, Jane R (2009) Treatment of patients with simplesnoring. Arch Bronconeumol 45:508-515]. Existing non-invasive methodsare of limited use, e.g., they do not eliminate the cause of sleepapnea, are in-efficient, and are uncomfortable (e.g., such as in thecase of CPAP devices). Moreover, the surgical procedures available todayinvolve the need for local or general anesthesia and have thepossibility of postoperative complications.

Another known technique for treating snoring is the use of lasertherapy. Laser therapy has been shown to increase wound healing andcollagen remodeling. In particular, the use of lasers in the treatmentof snoring dates back to early 1990 when Kamami used a laser to performlaser-assisted uvulopalatoplasty (LAUP), which results in tissuereduction of the soft palate under local anesthesia. [Refs Kamami Y V(1990) Laser CO ₂ for snoring. Preliminary results. AcataOtorhinolaryngol Belg 44:451-456]. However, Kamami's laser treatmentalways involved ablating or cutting the tissue for the purpose ofremoving swaths of tissue from a patient.

Recently, studies have shown that Er:YAG based lasers can help inreducing the severity of snoring and improve the quality of sleepwithout the need for anesthesia by tightening the soft palate tissue,mainly the oral mucosa. The tissue tightening is governed by two mainprinciples: 1) collagen denaturation resulting in collagen shrinkage andtissue tightening and 2) wound healing response that generates newcollagen and elastin. The oral mucosa consists of two layers: 1) surfacestratified Squamous Epithelium and 2) the Lamina propria which is madeof a fibrous connective tissue laser that consists of a network of typeI and III collagen and elastin fiber. Contraction occurs from the heatinduced protein denaturation, dehydration of collagen above 60° C.

In particular, the use of laser energy at 2940 nm has been demonstratedto produce photothermal effect that results in shrinkage of collagenfibers in the pharyngeal and palatal soft tissues. [Ref Majaron B,Srinivas S M, He H, Nelson J S (2000) Deep coagulation of dermalcollagen with repetitive Er:YAG laser irradiation. Laser Surg Med26:215-222]. [Beltram M, Drnovsek-Olup B (2004) Histological andbiomolecular analysis of new collagen synthesis after “SMOOTH” mode Er;YAG laser skin resurfacing. Posters. Lasers Surg Med 34:56]. Treatmentwith Er:YAG lasers typical entails three treatment sessions performed at2 to 4 week intervals and are performed with a power of about 7 Watts, atypical fluence of about 2 J/cm², and about 15,000 pulses per treatment.A typical snoring prevention treatment session takes about 30-45minutes.

Despite the advances made by Er:YAG laser treatments, there is stillopportunity for significant improvement. For example, the 30-45-minutetreatment time is long and can be onerous for patients needing to sitstill in an operating chair during the procedure. Accordingly, a needexists for an improved laser-based treatment technique for treatment ofsoft tissue.

SUMMARY OF THE INVENTION

In view of the foregoing, it is desirable to provide an improvedtechnique for soft tissue treatment, e.g., shrinking, tightening andincreasing stiffness of the oral mucosa using an efficient, fast,anesthesia free procedure using a laser source. The present inventionprovides such a technique and relates to an improved laser-basedtreatment device for treatment of soft tissue that uses a laser sourcethat operates in the 9 μm to 11 μm wavelength range, e.g., a CO₂ laser.CO₂ lasers have several advantages over Er:YAG lasers in soft tissueapplications. For example, CO₂ lasers have an order of magnitude lowerabsorption coefficient than Er:YAG lasers in soft tissue which makes itmore desirable for the treatment of soft tissue. Furthermore, CO₂ lasershave a deeper thermal effect into soft tissue (e.g., about 200 μm) thanEr:YAG lasers and, therefore, have a greater capacity for collagendenaturation, thus requiring fewer treatment sessions a lower fluence(e.g., less than 0.2 J/cm²). This results in less energy and surfacedamage and, as a result, a faster treatment time.

The present invention features a handpiece for directing radiation(e.g., a laser beam) in the near- to far-infrared spectra (e.g., 9-11 μmwavelength range), to allow for treatment of soft tissue in the oralcavity with optimal efficiency, minimal technique sensitivity, and afast treatment time.

The system can be adapted to scan the laser beam using any knownscanning technique, e.g., galvo-mirrors. The laser beam can be scannedacross the treatment region using particular pattern(s) to allow forefficient energy delivery, producing enough localized photothermaleffect to contract collagen without damaging (burning or charring) ofthe tissue. Such patterns are described in more detail in U.S. PatentPublication No. 20170319277, which is incorporated herein by referencein its entirety. In various embodiments, laser radiation provides enoughenergy to increase the biomechanical stiffness of the soft tissue suchthat it is fully contracted without further damage or charring of thetissue.

In some embodiments, the system includes a handpiece with an opticalcartridge inserted inside that modifies the beam size to provide adifferent (larger or smaller) beam size than the original laser beamsize. The optical cartridge enables the use of high power lasers in anon-ablative procedures by modifying the beam size using optical lensesmounted in the optical cartridge hence optimizing the fluence and/orenergy density and further reducing the time of procedure.

Various aspects of the present invention include delivery of laserpulses with non-ablative energy levels to induce thermal heating on thesurface of the pharyngeal and palatal soft tissue but does exceed athreshold value (e.g., about 65° C.).

The system may also include a laser source controller than can adjustone or more parameters of the radiation (e.g., laser pulse duration)according to the type of treatment selected and/or the type of tissuebeing treated. For example, during treatment, the laser beam may bedirected to the treatment area, allowing for delivery of a specifiedenergy profile at or near the treatment area.

In general, in one aspect, embodiments of the invention feature a systemfor contracting an area of soft tissue. The system can include a CO₂laser source for generating a plurality of laser pulses of a laser beamhaving a wavelength in a range from 9 μm to 11 μm, a beam guidancesystem for directing the plurality of laser pulses to respective tissuelocations within the soft tissue area, and a controller adapted tocontrol the CO₂ laser source and the beam guidance system to achieve atherapeutically effective contraction of the soft tissue area at a rateof 1 cm² in no more than 25 seconds.

In various embodiments, each laser pulse has a fluence of no more than0.2 J/cm² and/or a duty cycle in a range from 0.1 to 5 percent. Thetherapeutically effective contraction can include at least 10 percent ofa full contraction of the soft tissue area. The beam guidance system candirect the plurality of laser pulses to respective tissue locations in apattern. The pattern can have a number of locations (e.g., 15 to 1500locations or 30 to 45 locations). The total pattern time can be in arange from 0.001 to 0.5 seconds. In some cases, the beam guidance systemcan repeat directing the plurality of laser pulses in the pattern toadditional different soft tissue area portions, to achievetherapeutically effective contraction of all of the soft tissue area.The area of soft tissue can be located in a back of a throat andtherapeutically effective contraction of all of the soft tissue area canbe achieved during a total treatment time in a range from 3 to 20 min.In some cases, the pattern includes a first tissue location, at leastone location non-adjacent to the first tissue location, and a locationadjacent to the first tissue location. A quantity of the at least onelocation non-adjacent location can be determined based at least in parton a thermal relaxation time of the soft tissue.

In various embodiments, the system can also include a handpiece formingan exit orifice and operatively connected to the beam guidance systemfor delivering the laser beam to the soft tissue area. In some cases,the exit orifice can direct the laser beam toward the soft tissue areaalong an exit axis substantially aligned with a longitudinal axis of thehandpiece. The handpiece can also include a focusing optic and at leastone lens (e.g., two lenses) disposed between the beam guidance systemand the exit orifice. The focusing optic and the at least one lens cancooperate to increase a diameter of the laser beam (e.g., a collimatedlaser beam). In some instances, the laser beam has a working range(defined below) in a range from 1 cm to 5 cm.

In general, in another aspect, embodiments of the invention feature amethod for contracting an area of soft tissue. The method can includethe steps of generating a plurality of laser pulses of a laser beamhaving a wavelength in a range from 9 μm to 11 μm using a CO₂ lasersource; and directing the plurality of laser pulses to respective tissuelocations within the soft tissue area, such that a therapeuticallyeffective contraction of the soft tissue area is achieved at a rate of 1cm² in no more than 25 seconds.

In various embodiments, each laser pulse has a fluence of no more than0.2 J/cm² and/or a duty cycle in a range from 0.1 to 5 percent. Thetherapeutically effective contraction can include at least 10 percent ofa full contraction of the soft tissue area. The directing step caninclude directing the plurality of laser pulses to respective tissuelocations in a pattern. The pattern can have a number of locations(e.g., 15 to 1500 locations or 30 to 45 locations). The total patterntime can be in a range from 0.001 to 0.5 seconds. In some cases, thedirecting step includes directing the plurality of laser pulses in thepattern to additional different soft tissue area portions, to achievetherapeutically effective contraction of all of the soft tissue area.The area of soft tissue can be located in a back of a throat andtherapeutically effective contraction of all of the soft tissue area canbe achieved during a total treatment time in a range from 3 to 20 min.In some cases, the pattern includes a first tissue location, at leastone location non-adjacent to the first tissue location, and a locationadjacent to the first tissue location. A quantity of the at least onelocation non-adjacent location can be determined based at least in parton a thermal relaxation time of the soft tissue. In some instances, thelaser beam has a working range (defined below) in a range from 1 cm to 5cm.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. In the following description,various embodiments of the present invention are described withreference to the following drawings, in which:

FIG. 1A is a side cross-sectional schematic view of a straight handpieceand optical cartridge, according to various embodiments;

FIG. 1B is a side cross-sectional schematic view of a straight handpieceincluding a tongue depressor, according to various embodiments;

FIG. 2 is an example plot of a beam size diameter that defines a workingrange of the native beam where the beam is collimated, according tovarious embodiments;

FIG. 3 is a microscope image illustrating soft tissue shrinkage inchicken skin before and after laser irradiation, according to variousembodiments;

FIGS. 4 a-4 b are example plots of percentage collagen contraction tofull contraction as a function of power and lasing time, respectively,according to various embodiments;

FIG. 4 c is an example 3D plot combining the data shown in FIGS. 4 a and4 b;

FIG. 5 is an example plot of biomechanics data of the measured stiffnessof excised rat tissues of the lased group and compared to the controlgroup in an animal study, according to various embodiments;

FIG. 6 is a plot of histology data of collagen contraction of excisedrat tissues of the lased group and compared to the control group in ananimal study, according to various embodiments;

FIG. 7 is a chart providing example laser and treatment parametervalues, according to various embodiments; and

FIG. 8 is a schematic perspective view of a dental laser system,according to various embodiments.

DETAILED DESCRIPTION

Various embodiments of the present invention are directed to an improvedlaser treatment device that overcomes the shortcomings of conventionalsoft tissue treatment devices, e.g., with improved energy delivery,treatment time and number of treatments required to achieve effectivetherapeutic effect and without damaging the tissue or causing pain tothe patient. The device can include a hand piece that delivers (i) laserpulses that heats the tissue without damage to therapeutically effectivecontraction, (ii) a laser beam having a long working range (definedbelow), and (iii) coolant (air, water, etc.) to an oral treatmentregion. The oral treatment area may include, for example: soft palate,uvula, palatine tonsils and the back of tongue; however, these arenon-limiting examples. In general, any suitable tissue region can betreated.

For some applications, a CO₂ laser source operating at a wavelength in arange of 9-11 μm (e.g., 9.3 μm, 10.6 μm), is desirable for suchtreatments. For example, CO₂ lasers can be delivered using a handpiece1. As shown in FIG. 1A, the handpiece can have a straight configurationthat can enable access to challenging locations in the mouth. In somecases, as shown for example in FIG. 1B, the handpiece can include anintegrated tongue depressor 10. The handpiece 1 can accomplish treatmentefficiently and with a fast treatment time and without need foranesthesia. Some advantages of the laser therapy described herein overconventional methods include increased collagen contraction andregeneration that leads to increased tissue stiffness with minimal painor sensation. Furthermore, treatment of the affected area using thelaser therapy described herein has a longer lasting effect (e.g.,contraction of the tissue lasts for a longer time) than conventionaltechniques, which can reduce the number of treatments needed (e.g., lessthan 2, 3, 4, 5, or 6 treatments per year).

The laser is pulsed and scanned in a certain pattern to allow optimalcollagen contraction of the oral mucosa and other soft tissue andminimal heat accumulation. In some embodiments, the delivery of acollimated laser beam is achieved by a handpiece 1, which may bestructured and designed to receive an optical cartridge 2. The opticalcartridge 2 can include at least one optical lens to modulate a laserbeam passing therethrough. For example, as shown in FIG. 1A, the opticalcartridge can include an upstream optical lens 3 and a downstreamoptical lens 4. The optical cartridge 2 can be mounted to the handpiece1 using any known technique, e.g., with a threading 6. The ability toreplace or remove the optical cartridge 2 allows switching the laserbetween treatment modes, such as an ablative mode to a non-ablative modeand vice versa. In addition, tubing 5 in the handpiece may be used todeliver cooling fluids (e.g., air, water, and combinations thereof) toprovide cooling of the tissue surface and avoid any contaminants fromreaching the optics. The tubing 5 can be sealed using known techniques.

In addition, the optical cartridge 2 can provide a laser beam having along working range. As used herein the term “working range” means thedistance along the length of the laser beam at which the laser beam hasa fluence capable of treating the tissue (e.g., capable of fullycontracting the tissue). Conventional devices have a relatively shortworking range, typically focused tightly around the focal point of thelaser beam, out of a desire to not waste any energy along the length ofthe laser. The laser treatment device of the present invention can, insome embodiments, tolerate a longer working range, so as to enable anoperator to move his/her hand (and, corresponding, the laser beam),while still treating the treatment area. The concept of a working rangeis described in more detail with reference to the phrase “depth oftreatment” (which can be interchanged with “working range”) in U.S.Patent Publication No. 20160143703, which is incorporated by referenceherein in its entirety. In other words, in certain embodiments, theamount of energy on the target tissue does not change over a relativelylong distance (e.g., more than 0.5 cm, more than 1 cm, more than 1.5 cm,more than 2 cm, more than 3 cm, more than 4 cm) to accommodate for handmovements and variability in the user's holding of the handpiece and toaccommodate for human factors. FIG. 2 , for example, is a plot showingexemplary beam diameter measurements at a distance from an end of thehandpiece 1. As shown, in this example, the beam diameter does notchange over a range of 25 mm.

In various embodiments, laser parameters (e.g., shown in FIG. 7 , power,repetition rate, pulse duration, and/or laser beam overlap) may beselected to optimize efficiency and to contact tissue without damage.Moreover, the laser source may be spatially scanned to provide differentpulse energies at different locations.

FIG. 3 shows two microscope images of chicken tissue before and afterlasing with the CO₂ laser. The features on the surface of the tissue arecontracted closer together as a result of heat induced contractionthroughout the tissue. The cross linking between collagen fibrils aredisrupted resulting in a collapse of collagen fibrils into a lowerentropy state.

For an efficient treatment, contraction of the soft tissue withoutdamage or charring is desirable. One of the major mechanisms underlyingthe clinical effect of tissue tightening is a structural change in thecollagen polymer induced by thermal energy, causing collagen shrinkage.Collagen is the most abundant protein in soft tissue and it is a polymerthat exists as a triple helix with chains held together by hydrogenbonds. When enough thermal energy is delivered to collagen, there isdenaturation of the collagen triple helix into a haphazard coil pattern.The heat-stable intermolecular crosslinks are maintained within the newcollagen configuration which leads to increased tension within thecollagen as the structure shrinks and thickens. Thermal treatment oftissues triggers a wound healing response, which includes three phases.In the first proliferation phase Collagen I-III is produced; in thesecond phase, fibroblasts differentiate into myofibroblasts and causetissue contraction; and in the third remodeling phase, the tissuebecomes more compact and there is an increase in collagen. Heat-inducedcollagen denaturation depends on both the amount of thermal powerdelivered (see FIG. 4 a ) and the amount of time of thermal treatment(see FIG. 4 b ). If too much thermal power is delivered to the tissue, adamage threshold is exceeded and the tissue is ablated, burned, orcharred. As used herein, the damage threshold refers to any combinationof laser treatment parameters that causes the tissue to ablate, burn, orchar. As used herein, in one embodiment, the term full contractionrefers to contraction of the tissue within a predetermined percentage ofthe damage threshold, which in some cases can be the contraction of thetissue at the damage threshold, generally as a function of at least oneof power and lasing time. The predetermined percentage within which fullcontraction is of the damage threshold can be, in various embodiments,in a range from 25%-0.01%, in a range from 20%-1%, in a range from15%-3%, and in a range from 10%-5% (e.g., 25%, 20%, 15%, 10%, 7%, 5%,3%, 1%, 0.5%, 0.3%, 0.1%, 0.07%, 0.05%, 0.03%, and 0.01%). In certaincommercial applications, tissue will only be contracted to within acertain safety margin of the damage threshold, to avoid potential harmor discomfort to the patient.

As used herein, the term therapeutically effective contraction refers toan amount of contraction that is a predetermined percentage of fullcontraction. The predetermined percentage of full contraction can be, invarious embodiments, in a range from 5% to 100%, in a range from 10% to95%, in a range from 15% to 90%, in a range from 20% to 85%, in a rangefrom 25% to 80%, in a range from 30% to 75%, in a range from 35% to 70%,in a range from 40% to 65%, in a range from 45% to 60%, and in a rangefrom 50% to 55%. As examples, in various embodiments, the predeterminedpercentage of full contraction can be: at least 5%, at least 10%, atleast 15%, at least 20%, at least 25%, at least 30%, at least 35%, atleast 40%, at least 45%, at least 50%, at least 55%, at least 60%, atleast 65%, at least 70%, at least 75%, at least 80%, at least 85%, atleast 90%, at least 95%, at least 96%, at least 97%, at least 98%, andat least 99%. In general, therapeutically effective contraction resultsin a reduction of snoring that lasts for a therapeutically andcommercially effective period of time (e.g., a week, several weeks, amonth, several months, a year, several years, or longer).

FIG. 4 a is a plot with example data showing the effect of laserradiation power on percentage contraction. In this example, an optimalaverage power irradiation of 1.5 Watts can result in full contractionwhile remaining below the damage threshold. However, in otherembodiments with, e.g., different operating conditions or laserparameters, different average power amounts can be used. For example,average power can be in a range from 0.1 Watts to 5 Watts, 0.5 Watts to4.5 Watts, 1 Watt to 4 Watts, 1.5 Watts to 3.5 Watts, and 2 Watts to 3Watts. In various embodiments, average power can be about 0.5 Watts, 1Watt, 1.5 Watts, 2 Watts, 2.5 Watts, 3 Watts, 3.5 Watts, 4 Watts, 4.5Watts, and 5 Watts. FIG. 4 b is a plot with example data showing theeffect of lasing time on percentage contraction at a single treatmentlocation. In this example, an optimal lasing time of about 1.8 secondscan result in full contraction of a 1 cm² tissue portion while remainingbelow the damage threshold. However, in other embodiments with, e.g.,different operating conditions or laser parameters, different lasingtimes can be used. For example lasing time can be in a range from 0.1seconds to 2 minutes, 1 second to 90 seconds, 5 seconds to 60 seconds, 7seconds to 55 seconds, 9 seconds to 50 seconds, 11 seconds to 45seconds, 13 seconds to 40 seconds, 15 seconds to 35 seconds, 17 secondsto 30 seconds, 20 seconds to 25 seconds, 0.1 seconds to 5 seconds, 0.5seconds to 4.5 seconds, 1 second to 4 seconds, 1.5 seconds to 3.5seconds, and 2 seconds to 3 seconds. In various embodiments, lasing timecan be no more than 0.5 seconds, no more than 1 second, no more than 1.5seconds, no more than 1.6 seconds, no more than 1.7 seconds, no morethan 1.8 seconds, no more than 1.9 seconds, no more than 2 seconds, nomore than 2.5 seconds, no more than 3 seconds, no more than 3.5 seconds,no more than 4 seconds, no more than 4.5 seconds, no more than 5seconds, no more than 7 seconds, no more than 10 seconds, no more than15 seconds, no more than 20 seconds, no more than 25 seconds, no morethan 30 seconds, no more than 40 seconds, no more than 50 seconds, nomore than 1 minute, no more than 90 seconds, no more than 2 minutes.

The above lasing times are example lasing time ranges for the treatmentof a 1 cm² portion of soft tissue. However, as used in this application,this disclosure should be interpreted as support for a rate oftreatment, meaning the disclosed lasing times are the amount of time itwould take to treat a 1 cm² portion, but that rate of treatment can beused to treat a smaller or larger area. As one example, the disclosureof a lasing time of no more than 25 seconds should be interpreted assupport for treating at a rate of 1 cm² in no more than 25 seconds. Thisrate of treatment can be extrapolated down or up to determine an amountof time required to treat a smaller area, e.g., 1 mm² in 0.25 seconds ora larger area, e.g., 10 cm² in 250 seconds. Moreover, even though therate of treatment is expressed as a unit of 2-dimensional area permeasure of time, in various embodiments, the supported rates oftreatment can be used to treat any portion of the soft tissue, including2-dimensional and 3-dimensional portions, using conventional geometricand mathematical conversion techniques. For example, the supported ratesof treatment can be used to treat discrete points, lines (linear andnon-linear), circle perimeters, volumes, and any other portion of thesoft tissue. FIG. 4 c is a 3D plot combining the data shown in FIGS. 4 aand 4 b . The other laser parameters that were held constant as time andpower were varied are shown in a chart on FIG. 4 c.

In various embodiments, a therapeutically effective contraction can beachieved by operating the laser such that a predetermined number ofpulses are delivered during a predetermined period of time sufficient toaccomplish the therapeutically effective contraction. For example, laserpulses can be delivered at the following rates: a sequence of 15 pulsesin a range of 0.1 msec to 49 msec, 1 msec to 45 msec, 2 msec to 40 msec,3 msec to 35 msec, 4 msec to 30 msec, 5 msec to 25 msec, 6 msec to 20msec, 7 msec to 15 msec, and 8 msec to 10 msec. The precedingdescription provides support for various rates of treatment (secs/pulse)and can be extrapolated up or down for the delivery of any number ofpulses using known mathematical techniques. In some cases, theextrapolation can be based on equal time spacing between pulses (e.g.,15 pulses in 49 msec is a rate of 3.3 msec per pulse). In anotherexample embodiments, laser pulses can be delivered at a rate of 37pulses in 0.118 sec (or 3.2 msec per pulse). In other cases, theextrapolation can be based on different time spacing between the pulses.

Irradiation of soft tissue with a lower power level laser results inincreased stiffness and contraction. For example, an animal study wasconducted to measure these characteristics. The animal study includedtwo different groups of rats. A lased group, which was irradiated with alaser, and a control group, which was not exposed to any laserirradiation. The irradiation of the lased group was performed in onesession with an average CO₂ laser power of 1.5 Watts over a period of 10seconds per rat. The fluence was about 0.16 J/cm² achieved by a nativebeam diameter of 2 mm (1/e²) measured by knife edge technique. Thenative beam was scanned in a certain pattern with specific parameters,e.g., a combination of those listed in FIG. 7 , as for example. The sizeof the pattern was 7 mm, which was chosen in part because it was largeenough to visualize a change of the target tissue.

Collagen shrinkage (contraction) and biomechanical tissue stiffness weremeasured at three different time points, 24 hours, 21 days and 35 daysafter the irradiation session for each of the lased (n=10) and controlgroups (n=5). At each of the time points, a section of the soft palatewas excised and divided into two samples, one section to obtainhistology data to quantify collagen denaturation and another section toobtain stiffness data to quantify biomechanics characteristics bymeasuring the Young's modulus (KPa). FIG. 5 shows the stiffness resultsof the excised tissue, from both the lased and control groups, at thethree time points mentioned above. As shown, the lased group exhibited atenfold increase in stiffness at each time point over the control group.In this example experiment, the mean stiffness values for the controlgroups were 1.0±0.17 kPa at day 1, 1.7±0.17 kPa at day 21, and 1.6±0.63kPa at day 35. No significant difference was found between the threecontrol groups (p>0.05). The mean stiffness values for the treatmentgroups were 25±18 kPa for day 1, 29±19 kPa for day 21, and 97±113 kPafor day 35. No significant difference was found between the threetreated groups (p>0.05). The increase in stiffness of the treated animaltissues was maintained at over an order of magnitude over that of thecontrols (p≤0.002 for each time point). These data are one example ofachievable results. In various embodiments, laser treatment of the softtissue as described herein can result in a stiffness increase of thetissue in a range from 1.1-fold to 250-fold, 1.1-fold to 100-fold,1.5-fold to 95-fold, 2-fold to 90-fold, 5-fold to 85-fold, 7-fold to80-fold, 10-fold to 70-fold, 12-fold to 60-fold, 15-fold to 40-fold, and20-fold to 30-fold. For example, laser treatment can result in astiffness increase of the tissue of at least 2-fold, at least 5-fold, atleast 10-fold, at least 15-fold, at least 20-fold, at least 25-fold, atleast 30-fold, at least 40-fold, at least 50-fold, at least 60-fold, atleast 70-fold, at least 80-fold, at least 90-fold, at least 100-fold,and at least 250-fold. In various embodiments, soft tissue thatundergoes laser treatment as described herein can, over the period in arange from 2 weeks to 6 weeks (e.g., 1 month), undergo an increase instiffness in a range from 1.1-fold to 10-fold, 2-fold to 9-fold, 3-foldto 8-fold, 4-fold to 7-fold, and 5-fold to 6-fold. For example, lasertreatment can result in a stiffness increase of the treated tissue of atleast 1.1 fold, at least 1.5-fold, at least 2-fold, at least 3-fold, atleast 4-fold, at least 5-fold, at least 6-fold, at least 7-fold, atleast 8-fold, at least 9-fold, and at least 10-fold.

The measured increase in stiffness over the 2 week to 6 week rangeconfirms that the soft tissue biomechanical changes persist into theremodeling phase, which can be based on the duration of the fibrosis orotherwise altered collagen structure according to the wound healingprocess. Therefore, the increased stiffness can be maintained forsignificantly longer periods without significant deterioration. Forexample, in various embodiments, the stiffness values can decrease by ina range of 0.1% to 30%, 2% and 25%, 3% and 20%, 4% and 15%, and 6% and10%, e.g., less than 30%, less than 25%, less than 20%, less than 15%,less than 10%, less than 5%, and less than 1% over any of the followingtime periods following the increase in stiffness measured in the rangeof 2 weeks to 6 weeks following treatment: at least 1 month, at least 3months, at least 6 months, at least 9 months, at least 12 months, atleast 15 months, at least 18 months, at least 21 months, and at least 24months.

Similarly, the histology data show increased collagen shrinkage for thelased group and remains higher than that of control over the three timepoints, as shown in FIG. 6 . In this example experiment, the meancollagen histopathological values for control groups were 0.20±0.45 forday 1 and 0 for days 21 and 35. No significant difference was foundbetween the three control groups (p>0.05). The mean collagenhistopathological values for the lased groups were 2.7±1.0 for day 1,1.9±0.78 for day 21, and 2.8±0.63 for day 35. No significant differencewas found between the three treated groups (p>0.05). An overall changefrom baseline persisted through the inflammation stage (day 1) and intothe tissue remodeling stages (days 21 and 35). These data are oneexample of achievable results. In various embodiments, laser treatmentof the soft tissue as described herein can result in a histopathologicalvalue increase of the tissue in a range from 1.1-fold to 250-fold,1.1-fold to 100-fold, 1.1-fold to 50-fold, 1.5-fold to 47-fold, 2-foldto 45-fold, 4-fold to 43-fold, 6-fold to 40-fold, 8-fold to 35-fold,10-fold to 30-fold, 12-fold to 25-fold, and 14-fold to 20-fold. Forexample, laser treatment can result in a histopathological valueincrease of the tissue of at least 2-fold, at least 4-fold, at least6-fold, at least 8-fold, at least 10-fold, at least 12-fold, at least14-fold, at least 20-fold, at least 25-fold, at least 30-fold, at least35-fold, at least 40-fold, at least 45-fold, at least 50-fold, at least100-fold, and at least 250-fold. In various embodiments, soft tissuethat undergoes laser treatment as described herein can, over the periodin a range from 2 weeks to 6 weeks (e.g., 1 month), undergo an increasein histopathological value in a range from 1.02-fold to 10-fold,1.05-fold to 9-fold, 1.1-fold to 8-fold, 1.5-fold to 7-fold, 2-fold to6-fold, 3-fold to 5-fold, 1.02-fold to 1.1-fold, 1.03-fold to 1.09-fold,1.04-fold to 1.08-fold, and 1.05-fold to 1.07-fold. For example, lasertreatment can result in a stiffness increase of the treated tissue of atleast 1.02-fold, at least 1.04-fold, at least 1.06-fold, at least1.08-fold, at least 1.1-fold, at least 1.2-fold, at least 1.3-fold, atleast 1.5-fold, at least 2-fold, at least 3-fold, at least 4-fold, atleast 5-fold, at least 6-fold, at least 7-fold, at least 8-fold, atleast 9-fold, and at least 10-fold. The measured increase inhistopathological value over the 2 week to 6 week range confirms thatthe soft tissue biomechanical changes persist into the remodeling phase,which can be based on the duration of the fibrosis or otherwise alteredcollagen structure according to the wound healing process. Therefore,the increased histopathological value can be maintained forsignificantly longer periods without significant deterioration. Forexample, in various embodiments, the stiffness values can decrease by ina range of 0.1% to 30%, 2% and 25%, 3% and 20%, 4% and 15%, and 6% and10%, e.g., less than 30%, less than 25%, less than 20%, less than 15%,less than 10%, less than 5%, and less than 1% over any of the followingtime periods following the increase in histopathological value measuredin the range of 2 weeks to 6 weeks following treatment: at least 1month, at least 3 months, at least 6 months, at least 9 months, at least12 months, at least 15 months, at least 18 months, at least 21 months,and at least 24 months. [Ref Von Den Hoff J. W., Maltha J. C.,Kuijpers-Jagtman A. M. (2006) Palatal Wound Healing: Effects of Scarringon Growth. In: Berkowitz S. (eds) Cleft Lip and Palate. Springer,Berlin, Heidelberg. https://doi.org/10.1007/3-540-30020-1_20].

The measured increase in stiffness and/or histopathological valuebetween 21 days and 35 days is important because it indicates theformation of new collagen during the proliferation phase of the woundhealing process. In addition, the measured results indicate that theincreased stiffness of the tissue, caused initially by thecontraction/disruption of collagen, persisted through the inflammatoryphase and into the tissue remodeling phase, rather than softening orbreaking down as the tissue changed structure. Over time, collagen wasrecruited, causing a thickening of the Lamina propria, which wasindicative of a maturing fibrosis. This means that the effect can lastfor several months and up to 1-2 years or more. [Ref F Wherhan, SSchultze-Mosgau, H Schliephake “Salient Features of the Oral Mucosa”Essential Tissue Healing of the Face & Neck]. The fibrosis-likeformation may be the desired result to provide a lasting benefit in thereduction of snoring vibrations.

In some variations, radiation emitted by a laser source may betransmitted through the handpiece 1 accompanied by mist and/or air. Thecooling is carried through tubings 5 that run along the handpiece 1 andcircumvent the optical cartridge 2. The cooling might be useful toreduce any unintentional heating of the tissue, as for example, if thehandpiece 1 dwells for a long time at the same location and is not movedalong the back of the throat.

In certain embodiments, the CO₂ laser is accompanied with a marking beam(e.g., green in color) that serves as a guidance of the location of thelaser beam on the target tissue. In other embodiments, the irradiationof the laser may consist of a pattern. A visual or sonar feedback can beintegrated within the system to indicate to the user the need to move toa new target area. A visual feedback to move for a new target area caninclude a stationary guidance beam (e.g., a green point can be seen onthe tissue). For example, while the tissue is being exposed to thelaser, a pattern is displayed on the tissue. When enough dose of energyhas been delivered in a pattern to contract collagen, the laser can stopscanning and a point object can be projected on the target tissue.Alternatively, a sonar feedback can include a sound emerging from thesystem when the sequence of patterns or energy dose is delivered.

FIG. 7 is a chart including exemplary laser and operation parameters.Laser parameters (e.g., power, repetition rate, pulse duration, andlaser beam overlap) may be designed to have an optimal outcome ofefficiency to remove diseased tissue or bone without damaging thematerial (i.e., optical cartridge 2) itself. However, the laser sourcemay be spatially scanned to provide different pulse energy at differentlocations, as will be appreciated by those skilled in the art.

FIG. 8 is a schematic depiction of an exemplary laser treatment system100 that can be used for the laser treatments described in thisapplication. As shown, in some embodiments the treatment system 100 caninclude a laser source 8 and a beam guidance system 9. The system canalso include a controller 7 for controlling both the laser source 8 andthe beam guidance system 9. Additional details on the laser treatmentsystem 100 can be found in US Patent Publication No. 2014/0363784A1,which is incorporated by reference herein in its entirety.

Each numerical value presented herein is contemplated to represent aminimum value or a maximum value in a range for a correspondingparameter. Accordingly, when added to the claims, the numerical valueprovides express support for claiming the range, which may lie above orbelow the numerical value, in accordance with the teachings herein.Every value between the minimum value and the maximum value within eachnumerical range presented herein (including in the chart shown in FIG. 7), is contemplated and expressly supported herein, subject to the numberof significant digits expressed in each particular range.

Having described herein illustrative embodiments of the presentinvention, persons of ordinary skill in the art will appreciate variousother features and advantages of the invention apart from thosespecifically described above. It should therefore be understood that theforegoing is only illustrative of the principles of the invention, andthat various modifications and additions can be made by those skilled inthe art without departing from the spirit and scope of the invention.Accordingly, the appended claims shall not be limited by the particularfeatures that have been shown and described but shall be construed alsoto cover any obvious modifications and equivalents thereof.

What is claimed is:
 1. A system for contracting at least one soft tissuelocation, the system comprising: a laser source for generating aplurality of laser pulses of a laser beam; a beam guidance system fordirecting the plurality of laser pulses to the at least one soft tissuelocation; and a controller adapted to control the laser source and thebeam guidance system to achieve a predetermined percentage of fullcontraction of the at least one soft tissue location that occurs at adamage threshold of the at least one soft tissue location, wherein thepredetermined percentage of full contraction comprises 20 percent offull contraction achieved at a rate of 1 cm² in no more than 15 seconds.2. The system of claim 1, wherein the predetermined percentage of fullcontraction comprises 20 percent of full contraction achieved at a rateof 1 cm² in no more than 10 seconds.
 3. The system of claim 1, whereinthe laser beam has a working range having a length in a range from 1 cmto 5 cm.
 4. The system of claim 1, wherein each laser pulse is deliveredat a rate of up to 3.3 msec per pulse.
 5. The system of claim 1, whereineach laser pulse has a fluence of no more than 0.2 J/cm².
 6. The systemof claim 1, wherein each laser pulse comprises a duty cycle in a rangefrom 0.15 to 5%.
 7. The system of claim 1, wherein the beam guidancesystem is adapted to direct the plurality of laser pulses to each of theat least one soft tissue location in a pattern.
 8. The system of claim7, wherein the pattern comprises a total pattern time in a range from0.01 second to 0.5 second.
 9. The system of claim 7, wherein the beamguidance system is adapted to repeat directing the plurality of laserpulses in the pattern to additional different soft tissue area portions,to achieve the predetermined percentage of full contraction of all ofthe soft tissue area portions.
 10. The system of claim 7, wherein thepattern comprises a first tissue location, at least one locationnon-adjacent to the first tissue location, and a location adjacent tothe first tissue location.
 11. The system of claim 10, wherein aquantity of the at least one location non-adjacent location isdetermined based on a thermal relaxation time of the soft tissue. 12.The system of claim 1 further comprising a handpiece forming an exitorifice and operatively connected to the beam guidance system fordelivering the laser beam to the at least one soft tissue location. 13.The system of claim 12, wherein the handpiece further comprises afocusing optic and at least one lens disposed between the beam guidancesystem and the exit orifice.
 14. The system of claim 13, wherein the atleast one lens comprises two lenses.
 15. The system of claim 13, whereinthe focusing optic and the at least one lens are structured and arrangedto generate a collimated laser beam.
 16. The system of claim 13, whereinthe focusing optic and the at least one lens are structured and arrangedto increase a diameter of the laser beam.